The term “fingerprint” refers to uneven lines on a front surface of a tip of a human finger. In these uneven lines, convex portions are called ridges and concave portions are called valleys. As the fingerprint is lifetime invariant, unique, and convenient, it has become almost synonymous with biometrics identification.
Currently, a fingerprint identification of a display module mainly includes a contact-type fingerprint identification, and a fingerprint identification device is generally disposed in a non-display area such as at a home key or on a back surface of the display module. Trends in display module development are moving toward ultra-thinness, broad color spectra, wide visual ranges, and component integration. Some recent research has consequently focused on integrating fingerprint identification devices into display areas of display modules so as to realize an optical fingerprint identification. However, in a process of the optical fingerprint identification, if a distance between a finger and a sensor is large, the sensor may simultaneously receive light reflected by a plurality of ridges and/or valleys due to scattering of light reflected by the finger. As a result, fingerprint information identified based on the light received by the sensor may not be accurate. The improvement of accuracy in the identification of fingerprint information in optical fingerprint identification has consequently become a problem to be solved for those skilled in the art.